Hidden username mobile number using sub string Method

This concept make in username and password hidden in  user command an our website like classified website Ads so try this simple JavaScript hidden particular area name and mobile number.

JavaScript 

using this script in our body tag  edit our String and text var str="karthicktech77@gmail.com" and change the values sub string (0,3) or (1,4) in script 

<script type="text/javascript">  
var str="karthicktech77@gmail.com"  
document.write(str.substring(0,3)+"********")  
document.write(str.substring(14,30))  
</script>

PHP

Most of the classified site values shows in database just echo the value $email1 or Directly Enter the value 

<?php echo substr("$email1", 0, 3) ?>*****<?php echo substr("$email1", 13, 10) ?>